7x16 Mini Lathe
Thursday, Mar 30 2017
Where’d the lathe go?
I got a bit frustrated with the mis-aligned headstock and tailstock on my old lathe. I did some tests that I probably should have done a long time ago. Oh. The headstock wasn’t paralled to the ways. I played with it for a day and a half. It got better, but not good enough. I realized that I’d have to throw more time and money at the lathe than it probably was worth to get it where I wanted it to be.
One craigslist posting and two days later the lathe was in new hands. It sold for about what I’d spent getting it running — new motor, drive belt, 3-jaw chuck, etc. I’m not counting the cost of tooling. I’m keeping that for the new lathe. The entire story of the old lathe starts here.
New lathe? Yup, today a crate was delivered from Little Machine Shop containing their Model 5100 HiTorque 7x16 Mini Lathe. It was supposed to arrive yesterday but the shipping company loaded it on the wrong truck. Today they got the correct truck and it showed up about 11 AM this morning.
I removed it from the crate and put it on the table where the old lathe sat. It’s a bit shorter (16" between centers instead of 18") but has a larger swing – 7" vs 6". It’s a good size for me.
Pretty much everything was drenched in a sticky oil/grease. I removed pieces one-by-one, cleaning the sticky stuff with kerosene and lots of rags. Once the protective goo was gone I made sure to oil all surfaces.
I re adjusted everything to my liking as part of re-assembly. Well, I thought I did.I can see that I’ll need to put more work into that task so travel across the various ways is consistent the entire length of the way. That is not unexpected. I already needed to stone some rough edges found when cleaning.
I replaced the tool post that came with the lathe with the QCTP that I’d been using on the Craftsman. The picture also shows the chuck from the old lathe. It is mounted on a new arbor to match this tailstock.
So is is accurate? First tests show less than half a thousandth runout at the chuck alignment boss and the taper. That beats the .002" or more I got on the old lathe.
I took the chuck apart and cleaned the sticky goo. I used a molly grease for the tightening mechanism. It feels OK when put back together.
With the chuck back on the lathe I spun it at max RPM with some paper towels in place to catch any remaining oil/grease that got spun off. Good thing.
A test indicator on a 1/2" diameter test bar showed about .0015" runout. Acceptable for a 3-jaw chuck. Measurements show an vertical offset of .0015” high 10" from the headstock. The horizontal offset at 10" is .0045". I’ll try to do something about that. It is still much better out of the box than I was able to get the old lathe after a day and a half of trying.
More later. I need a carriage lock. And a carriage stop. And a cross slide lock. Etc.